Radio loud speaker



Nov. 10, 1931. c. H. DUFFY 1,831,484

- RADIO LOUD SPEAKER Filed April 11, 19:51 2 Sheets-Shee 1 Nov. 10, 1931.

c. H. DUFFY 1,831,484

RADIO 1.0m) SPEAKER Filed April 11, 1951 2 Sheets-Sheet 2 Patented Nov. 10, 1931 PATENT OFFHE CHARLES HUGH DUFFY, OF MIAMI, FLORIDA RADIO LOUD SPEAKER Application filed April 11, 1931. Serial No. 529,498.

(GRANTED UNDER THE ACT OF MARCH 3, 1883, AS AMENDED APRIL 30, 1928; 370 O. G. 757) This invention relates to radio loud speakers and the like but more particularly to a system for impressing sound producing pulsations on a vibratory diaphragm to the end that the tendency to cause the diaphragm to whip or chatter and thus set up false sound producing vibrations in the air is eliminated.

In the use of vibratory diaphragms of the type to which this invention is particularly directed, namely, a diaphragm of two flexed formations having a central meeting portion to which the pulsations are impressed, it is usual to connect the actuating unit or units m thereto, so that such pulsations will be impressed upon the diaphragm as diagrammatically indicated in Fig. 2 with the consequent disadvantages which will be hereinafter discussed.

As an alternative of the usual practice illustrated in Fig. 2, the actuating unit or units maybe connected to the diaphragm as diagrammatically illustrated in Figs. 3 and 5. While the disadvantages in the practice shown in Fig. 2 may be corrected by the alternative illustrated in Fig. 3, other disadvantages may follow from the latter, as will be hereinafter pointed out. The disadvantages flowing from the arrangements illustrated in these Figures 2 and 3 are corrected by the application of the system diagrammatically shown in Figs. 4 and 5, and structurally shown in Fig. 1, as will be now described.

Referring more particularly to the accompanying drawings:

Fig. 1 is a top plan view of a diaphragm showing two actuating unit-s connected to the central meeting portion of the two flexed diaphragm formations.

Figs. 2, 3, 4 and 5, are diagrammatic views, Fig. 2 being a side elevation and Figs. 3, 4 and 5 being top plan views.

Like numerals of reference indicate the same parts throughout the several figures, in

which:

1 indicates the diaphragm of two flexed formations. 2, meeting centrally at 3. 4 indicates the top and bottom ends of the diaphragm, and 5 the side edges thereof which are usually suitably clamped to hold the diaphragm in operative position.

6 indicates an actuating unit or units of the type wherein a pulsating armature pivoted and preferably balanced transmits its move ment to a pivoted transfer lever 7 by a connecting link 8.

For the purpose of a clear understanding of this disclosure, it is only necessary to illustrate diagrammatically the transfer lever 7 in Figs. 2, 3, 4 and 5, and to illustrate structurally the transfer lever 7 and the connecting link 8, by means of which the movement of the oscillating armature (not shown) is transmitted to the transfer lever 7.

With actuating units of this general type, it is usual to provide a driving pin 9 connected to the transfer lever 7 at one end and to the diaphragm at 7 at the other end so that the pulsations from the transfer lever 7 are impressed upon the diaphragm. In Fig. 1, the numeral 10 indicates a casing which enclosed the armature, pole pieces and field winding, which form no part of this invention per se.

The transfer lever 7 being usually a pivoted lever, the numeral 11 indicates the pivoted point or portion of said lever in all of the figures of the drawings, and since this lever is so pivoted, the movement of the end of said lever is an arcuate movement. Likewise the movement of the end of the driving pin 9 which is attached to the diaphragm is an arcuate movement the extent and direction of which relatively to the diaphragm for a given movement of the armature depends upon the length of the line (radius) between the point of connection 7 with the diaphragm and the pivotal point 11 of the transfer lever, and upon the angle which said line (radius) forms with the central vertical longitudinal plane of the diaphragm as in Fig. 2, and with the vertical transverse plane of the diaphragm as in Figs. 3 and 5.

The direction of this arcuate movement which is impressed upon the diaphragm is shown by the two headed arrows in Figs. 2, 3 and 5. In the first of these this movement is in the direction of the central vertical lonitudinal plane of the diaphragm, and there- ?ore the diaphragm is pulsated. The direction of this arcuate movement also lies upwardly and downwardly, so that the diaphragm is also pulsated upwardly and downwardly. For the highest efliciency, diaphragms of this type should not be pulsated upwardly and downwardly, but only in the direction of the central vertical longitudinal plane thereof. By making the driving pin 9 somewhat flexible, the up and down pulsation of the diaphragm may be reduced by the bending of the driving pin, but in practice such up and down movement of the diaphragm does in fact take place, while a more detrimental action is also imparted to the diaphragm. The driving pin 9 must be rigidly connected to the diaphragm. Therefore, the diaphragm 'under'the influence of pulsations of large amplitude actually takes the positions indicated but accentuated by the dotted and broken lines shown in Fig. 1. An analysis of'these lines in Fig. 2, shows that the upper end of the di apbragm has a greater amplitude of pulsation imparted to it, than the bottom end, and also shows that the central meeting portion of the diaphragm is rocked so that as the top end moves outwardly,the bottom end moves inwardly, and vice versa. This excessivemovement of the ends of the diaphragm is an unbalanced movement, and causes the ends of the diaphragm to whip or chatter and thus sets the entire diaphragm in a state of false vibra- 1311011 which greatly interferes With the purity of the reproduced sound, particularlythose of low frequency and large amplitude.

hen applying the drive unit or units to the diaphragm as shown in Fig. 3Qthe disadvantages present in Fig. 9. are overcome.

fact'with a properly balanced and con- .structed diaphragm, very satisfactory results ma be obtained with the arrangement shown in Fig.3, particularly when two drive units are employed as shown in Fig. 5 as will presently appear. However, I prefer to employ the arrangement shown in Fig. 4 and in Fig. 1.;either when one or two drive units are employed. 1

.However, it will be seen from Fig. 3., that the .arcuate movement at the point of attachment 7 of the driving pin 9 with the diaphragm is in'the direction of the double headed arrow, which movement is both in and out and crosswise of the central vertical longitudinal plane of the diaphragm. In this instance there is no up and down increment imparted to the diaphragm, nor any excessiyc movement imparted to the ends of the diaphragm, as in Fig. 1. There is. however, an unbalanced movement imparted to the two flexed portions of the diaphragm as will be seen from the dotted and broken lines in Fig. 3, and consequently a tendency to cause the central meeting portion to whip or chatter in a sidcwise or transverse direction, particularly when a single drive unit is employed.

These disadvantages are corrected by the system illustrated in Figs. 4 and 5. In Fig. 4 it will be seen that the drive unit is arranged at an angle to the central vertical longitudinal plane of the diaphragm so that the line '(radius) between the oint of connection 7 of the-driving Qmth the diaphragm and the pivot 11 ot tl ie transfer lever is substantially at right angles to said central vertical longitudinal plane of the diaphragm, and substantially parallel with the vertical transverse plane of the diaphragun. The result of this positioning of the drive unit that the direction of the arcuate movement of the point of connection 7 of the drive pin with the diaphragm, as indicated by the doubleheaded arrow in Fig. 4, is substantially in line with the central vertical longitudinal plane of the diaphragm and not crosswise of it as in Fig. 8.

lVith this brief discussion of the systelnnf positioningthe actuating unit or units with respect to the diaphragm to prevent crosswise whipping or chattering of the diaphragm, reference is made to Fig. 1, wherein two actuating units 6 are shown connected to the diaphragm. These units are established one above the other. It is preferable to space the units apart a distance which is substantially equal to onehalf theheight of the diaphragm, and to'position each unit equally distant from its adjacent end. This spacing is not critical, however, and may be varied as desired. This positioning of the units is also applicable to Fig. 5.

As shown in Fig. 1, the two actuating units 6 are reversed with respect. to the diaphragm and to each other and each unit positioned angularly to the vertical transverse plane of the diaphragm so that a line connecting the point of connection 7 of each unit with the diaphragmand the pivot 11 of each transfer lever are substantially parallel with the vertical transverse plane of the diaphragm. The result is that the arcuate movements of the pointsof connection 7- of the units with the diaphragm are as ind-icatedby the two double-headed arrows. While these arcuate movements are substantially in line with the central vertical longitudinal plane of the diato "Whip.0r chatter transversely is elimifingers 9 suitably secured to the transfer lever 7 and having their outer ends bent to form eyes 12 to receive a small machine screw 13 passed transversely through said eyes and the diaphragm. By means of the nut 1d the diaphragm is tightly clamped between the two fingers 9 so that there is no relative movement between these parts, and a permanent and highly efficient connection is provided.

Having thus fully described the invention,

it is apparent that by the positioning of the two actuating units reversely proposed, even the tendency for the diaphragm to whip and chatter transversely under the influence ofa single unit as in Fig. 3, will be substantially neutralized and ent1rely balanced out where two units are employed one above the otherand reversed, as in Fig. 5. So that .even when there is no provision for having the. arcuate movement of the point of connection lie substantially in line with the central vertical longitudinal plane of the diaphragm as in Fig. 1, the system shown in Fig. 3 may be satisfactorily used and particularly so where two units are employed and the one unit opposes the Whipping and chattering tendency of the other as in Fig. 5. The preferred construction and arrangement, however, is as shown in Fig. 1.

lVhat I claim as new and desire to secure by Letters Patent of the United States, is

1. A system for impressing sound producing pulsations on a vibratory diaphragn'i, including in combination with a diaphragm flexed into two roll formations and having a central meeting portion, two diaphragm actuating units, the position of one of the units being reversed with respect to the other, each unit-being disposed at the central meeting portion of the diaphragm and arranged at di'lferent points thereat, each unit including a pivoted transfer lever and means for connecting its transfer lever to the diaphragm at the central meeting portion of the diaphragm, the longitudinal axis of the transfer lever of each acuating unit being substantially paralranged so that the arcuate movements at the points of connection of the units with the diaphragm are substantially in line with the central vertical longitudinal plane of the diaphragm.

2. A system for impressing sound producing pulsations on vibratory diaphragm inding in combination with a diaphragm lied into two roll formations and having a central meeting portion, a plurality of diaphragm actuating units arranged for connection with the entral meeting portion of the dianhre units being with respect to the other, each unit including a pivoted transfer lever and means for connecting its transfer lever o the central meeting portion of the diaphragm, the longitudii'ial axis of the transfer lever of each actuating unit lying substantially parallel to the horizontal plane of the iohragm. with its pivotal portion and the n t 0.. connection of the unit with the diagm lying substantially parallel to the 'wical transverse plane of tne diaphragm,

hole arran ed so that the arcuate moveat the p i of connection of the units with the diaphragm are substantially in line with the entral vertical longitudinal plane of the diaphragm.

A system for impressing sound producilsations on a vibrator-v diaphragm, in in combination with a diaphragm into two roll forn'iations, a plurality of di; nuragm actuating units arranged for cor.-

.ection with the diaphragm, the position of the units being reversed with respect to each other, each uniu including a pivoted transfer lever and means for connecting its transfer lever to the diaphragm, the longitudinal axis of each transfer lever lying substantially parallel to the horizontal plane of the diaphragm, with its pivo al portion and the point of connection of the unit with the dia phragm lying substantially parallel to the vertical ti. sverse plane of the diaphragm, the whole arra and so that the arcu ate more ments at the points of connection of the units with the diaphragm are substantially parallel with the vertical longitudinal plane of the diaphragm.

l. A system for impressing sound producing pulsations on a vibratory diaphragm, including in combination with a diaphragm, a plurality of liaphragm actuating units ar- -ed for connection with the diaphragm, position of the units being reversed with re )ect to each other, each unit including a t ansfer lever and men .s for connect- 11 er lever to the di 'phragm, the axis of each transfer lever lying par el to the horizontal plane or th its pivotal poi ion and Hi i cion of the unit with the diaphragm substantially parallel to the vertical transverse olanc of the diaphragm, the

m, the position of one of the whole arranged so that the arcuate movements at the I oints of connection of the units with the diap iragm are substantially parallel with the vertical longitudinal plane of the diaphragm.

5. A system for impressing sound producing pulsations on a vibratory diaphragm, including in combination with a diaphragm, a plurality of diaphragm actuating units arranged for connection with the diaphragm, the position of the units being reversed with respect to each other, each unit including a pivoted transfer lever and means for connecting its transfer lever to the diaphragm, the longitudinal axis of each transfer lever lying substantially parallel to the horizontal plane of the diaphragm, the whole arranged whereby the resultant of the arcuate movements impressed upon the diaphragm is substantially parallel with the vertical longitudinal plane of the diaphragm.

6. A system for impressing sound producing pulsations on a vibratory diaphragm, including in combination with a diaphragm. aplurality of diaphragm actuating units arranged for connection with the diaphragm, the position of the units being reversed with respect to each other, each unit including a pivoted transfer lever and means for connecting its transfer lever to the diaphragm, the longitudinal axis of each transfer lever lying transversely of the diaphragm so that the arcuate movements imparted by one of the transfer levers to the diaphragm are bent oppositely to the arcuate movements imparted by the other of the transfer levers to the diaphragm, whereby the resultant of these arcuate movements is substantiall parallel with the vertical longitudinal plane of the diaphragm.

7. A system for impressing sound producing pulsations on a vibratory diaphragm, in cluding in combination with a diaphragm, a plurality of diaphragm actuating units arranged for connection with the diaphragm, each unit including means for imparting an arcuate movement to the diaphragm in a plane transversely of the diaphragm. the arcuate movement imparted by one unit being bent oppositely to the arcuate movement of the other unit so that the resultant of these arcuate movements is substantially a straight line.

8. A system for impressing sound producing pulsations on a vibratory diaphragm, including in combination with a diaphragm, a plurality of diaphragm actuating units for impressing pulsations on the diaphragm in an arcuate direction and in a plane transversely of the diaphragm, the arcuate line of the impressed pulsations of one unit bein bent oppositely to the arcuate line of the impressed pulsations of the other unit so that the resultant of the two arcuate lines is substantially straight.

9. A system for im ressing sound producing pulsations on a viliratory diaphragm, 1ncluding in combination with a diaphragm, a plurality of diaphragm actuatin units for impressing pulsations on the iaphragm, means for connecting one of the units to the diaphragm and normally tending to pulsate the diaphragm slightly laterally, and means for connecting the other of the units to the diaphragm and normally tending to pulsate the diaphragm slightly laterally, but oppositely to the first mentioned tendency, whereby both tendencies to pulsate the diaphragm laterally are substantially balanced and neutralized.

10. A system for impressing sound producing pulsations on a vibratory diaphragm, including in combination with a diaphragm, means for impressing pulsations on the diaphragm in oppositely bent arcuate directions, the resultant of which is substantially a, straight line.

11. A system for impressing sound producing pulsations of a vibratory diaphragm, including in combination with a diaphragm, means for impressing pulsations on the diaphragm tendin to whip the same transversely. and means for neutralizing the tendency of the diaphragm to whip transversely.

12. Means for preventing a diaphragm of the type described from whipping transversely under the influence of sound producing pulsations impressed upon it, including two oppositely disposed pulsation impressing devices. means for connecting said two pulsation impressing means to the diaphragm, to exert substantially equal and opposed whipping tendencies to the diaphragm.

13. A system for impressing sound producing pulsations on a vibratory diaphragm of two flexed roll formations having a central meeting portion, a diaphragm'actuating unit disposed at the central meeting portion of the diaphragm and including a pivoted transfer lever and means for connecting the transfer lever to the diaphragm at the central meeting portion of the diaphragm, the longitudinal axis of the transfer lever lying transversely of the diaphragm and disposed angularly to the central vertical longitudinal plane thereof so that the pivot of the transfer lever and the point of connection of the unit with the diaphragm lie parallel to the vertical transverse plane of the diaphragm, whereby the arcuate movement at the point of connection of the unit with the diaphragm is substantially in line with the central vertical longitudinal plane of the diaphragm.

14. A system for impressing sound producing pulsations on a vibratory diaphragm of two flexed roll formations having a central meeting portion, a diaphragm actuating unit arranged for connection with the central meeting portion of the diaphragm, the unit including a pivoted transfer lever and means for connecting the transfer lever to the central meeting portion of the diaphragm, the longitudinal axis of the transfer lever lying transversely of the diaphragm with its pivotal portion and the point of connection of the unit with the diaphragm lying substantially parallel to the vertical transverse plane of the diaphragm, so that the arcuate movement at the point of connection of the unit with the diaphragm'is substantially in line with the central vertical longitudinal plane of the diaphragm.

15. A system for impressing sound producing pulsations on a vibratory diaphragm, including in combination with a diaphragm flexed into roll formation, a diaphragm actuating unit arranged for connection with the diaphragm and including a pivoted transfer lever and means for connecting its transfer lever to the diaphragm, the longitudinal axis of the transfer level lying transversely of the diaphragm with its pivotal portion and the point of connection of the unit with the diaphragm lying substantially parallel to the vertical transverse plane of the diaphragm, so that the arcuate movement at the point of connection of the unit with the diaphragm is substantially parallel with the vertical longitudinal plane of the diaphragm.

16. A system for impressing sound producing pulsations on a vibratory diaphragm ineluding in combination with a diaphragm, an actuating unit arranged for connection with the diaphragm and including a pivoted transfer lever and means for connecting it to the diaphragm, the longitudinal axis of the transfer lever lying transversely of the diaphra gm with its pivotal portion and the point of connection of the unit with the diaphragm substantially parallel to the vertical transverse plane of the diaphragm, so that the arcuate movement at the point of connection of the unit with the diaphragm is substantially parallel with the vertical longitudinal plane of the diaphragm.

17. A system for impressing sound producing pulsations on a vibratory diaphragm, including in combination with a diaphragm, an actuating unit arranged for connection with the diaphragm and including a pivoted transfer lever and means for connecting it to the diaphragm, the longitudinal axis of the transfer lever lying transversely of the diaphragm and angularly to the vertical longitudinal axis of the diaphragm.

18. A system for impressing sound producing'pulsations on a vibratory diaphragm, including in combination with a diaphragm and actuating unit having a pivoted transfer lever lying transversely of the diaphragm and including means for connecting the transfer lever to the diaphragm and having the point of connection with the diaphragm and the pivotalpoint of the'tra'nsfer lever subsiantially parallel to the vertical transverse plane of the diaphragm, of means for correcting the tendency of the diaphragm to whip transversely, including an additional actuating unit reversed with respect to the first mentioned unit and having a pivoted transfer lever lying transversely of the diaphragm and in clud means for connecting the transfer lever to the diaphragm and having the point of connection with the diaphragm and the pivotal point of the transfer lever substantially parallel to the vertical transverse plane of the diaphragm.

it). A system for impressing sound producin pulsations on a vibratory diaphragm, including in combination with a diaphragm and actuating unit having a pivoted transfer lever lying transversely of the diaphragm and including means for connecting the transfer lever to the diaphragm and having the point of connection with the diaphragm and the pivotal point of the transfer lever substantially parallel to the vertical transverse plane of the diaphragm, of means for correcting the tendency of the diaphragm to whip transversely, including an additional actuating unit reversed with respect to the first mentioned unit ana means for connecting the additional actuating unit to the diaphragm.

20. A system for impressing sound producing pulsations on a vibratory diaphragm including in combination with a diaphragm and actuating unit having a pivoted transfer lever lying transversely of the diaphragm and including means for connecting the transfer lever to the diaphragm, of means for correcting the tendency of the diaphragm to whip transversely, including an additional actuating unit reversed with respect to the first mentioned unit and means for connecting the additional actuating unit to the diaphragm.

:21. A system for impressing sound producing pulsations on a vibratory diaphragm, includingin combination with a diaphragm an actuating unit having a pivoted transfer lever lying transversely of the diaphragm and including means for connecting the transfer lever to the diaphragm, of an additional actuating unit having a pivoted transfer lever lying transversely of the diaphragm and means for connecting the additional actuating unit to the diaphragm.

22. A system for impressing sound producing pulsations on a vibratory diaphragm, including in combination with a diaphragm having two flexed formations, and a central resting portion, of itactuating unit including means for connecting the same to the diaphragm, said connecting means including a pair of lingers in egral with the actuating unit and adapted to straddle the central meeting portion of the diaphragm and having means for receiving transversely of the fingers a fastening means, and a fastening means adapted to be passed transversely through the central meeting portion of the diaphragm and through the said fin' ers to clamp the meeting portion of the diap ragm between the said fingers.

23. A system for impressing sound producin pulsations on a vibratory diaphragm, incluc ing in combination with a diaphragm having two flexed formations, and a central meeting portion, of an actuating unit including means for connecting the same to the diaphragm, said conneciing means includin a pair of fingers integral with the actuating unit and adapted to straddle the central meeting portion of the diaphragm and means for clamping the central meeting portion of the diaphragm between the said fingers.

24. A system for impressing sound producin pulsations on a vibratory diaphragm, inclu ing in combination with a diaphragm, of an actuating unit including means for connecting the same to the diaphragm, saidconnecting means including a pair of fingers connected to the actuating unit at one end and adapted to straddle a portion of the diaphragm, and means forclamping the portion of the diaphragm between the said fingers. 25. A system for impressing sound producin pulsations on a vibratory diaphragm, inclu ing in combination with a diaphragm, an actuating unit having a pivoted transfer lever lying transversely of the diaphragm and including means for connecting the transfer lever to the diaphragm, of an additional actuating unit reversed with respect to the firstmentioned actuatin unit and having a pivoted transfer lever lying transversely of the diaphragm and means for connecting the additional actuating unit to the diaphragm.

"26. A s stem for im ressing sound producing pu sations on a vibratory diaphragm, including in combination with a diaphragm, an'actuating unit having a pivoted transfer lever normally tending to impress pulsations on the diaphragm in an arcuate direction, an additional actuating unit reversed with respect to the first mentioned actuating unit and having a pivoted transfer lever tending to impress pulsations on the diaphragm in an oppositely bent arcuate direction to that of the first mentioned actuating unit.

In testimony whereof I afiix my signature.

CHARLES HUGH DUFFY. 

